Martensitic transformations drive a multitude of emerging applications, which range from high stroke/high force actuation, magneto- and mechanocaloric refrigeration, to thermomagnetic and -elastic energy harvesting. All of these applications would benefit from faster transformations, but a comprehensive understanding of the fundamental factors determining the speed limits of martensitic transformations and their impact on microstructure as well as functional properties is still missing. To fulfill this foundational research gap, taking Ni-Mn-Ga epitaxially grown thin films as the model material system, I drive martensitic transformations in time scales ranging from several tens of milliseconds with flash lamp pulse down to the femtosecond range with laser pulse. The research aims to explore the martensitic transformation kinetics and microstructural evolution, ultimately paving the way to obtain a scale bridging understanding of time dependent processes and their impact on multiferroic properties. This talk will cover two key aspects: in-situ probing the transformation limits with synchrotron-based time-resolved x-ray diffraction and a systematic study of microstructure formation induced by fast heating and cooling via flash lamp annealing.
Yuru Ge received her BSc and MSc degree in Engineering in China. After that, she gained her second MSc degree in Materials Science at TU Chemnitz in Germany with Dr. Sebastian Fähler at IFW Dresden. Her thesis was focused on the deposition and characterization of ferromagnetic shape memory thin films. She is now an external PhD student at our chair. Yuru is working under Dr. Sebastian Fähler's day-to-day supervision at HZDR on time-dependency martensitic transformation based on ferromagnetic shape memory thin films.
Martensitic transformations drive a multitude of emerging applications, which range from high stroke/high force actuation, magneto- and mechanocaloric refrigeration, to thermomagnetic and -elastic energy harvesting. All of these applications would benefit from faster transformations, but a comprehensive understanding of the fundamental factors determining the speed limits of martensitic transformations and their impact on microstructure as well as functional properties is still missing. To fulfill this foundational research gap, taking Ni-Mn-Ga epitaxially grown thin films as the model material system, I drive martensitic transformations in time scales ranging from several tens of milliseconds with flash lamp pulse down to the femtosecond range with laser pulse. The research aims to explore the martensitic transformation kinetics and microstructural evolution, ultimately paving the way to obtain a scale bridging understanding of time dependent processes and their impact on multiferroic properties. This talk will cover two key aspects: in-situ probing the transformation limits with synchrotron-based time-resolved x-ray diffraction and a systematic study of microstructure formation induced by fast heating and cooling via flash lamp annealing.
Yuru Ge received her BSc and MSc degree in Engineering in China. After that, she gained her second MSc degree in Materials Science at TU Chemnitz in Germany with Dr. Sebastian Fähler at IFW Dresden. Her thesis was focused on the deposition and characterization of ferromagnetic shape memory thin films. She is now an external PhD student at our chair. Yuru is working under Dr. Sebastian Fähler's day-to-day supervision at HZDR on time-dependency martensitic transformation based on ferromagnetic shape memory thin films.
